对象的世界以及instanceof操作符 

 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title></title>
 6     <script>
 7         var Item = {
 8             construct:function(name){
 9                 this.name = name;
10             },
11             inspect:function(){
12                 print("it is",this.name,".");
13 
14             },
15             kick:function(){
16                 print("klunk!");
17             },
18             take:function(){
19                 print("you cannot lift",this.name,".");
20             }
21 
22         };
23         var lantern = Item.create("the brass lantern");
24         lantern.kick();
25 //extend方法克隆调用它的对象，然后将参数里传入的属性添加到克隆的对象上
26         var DetailedItem = Item.extend({
27             construct:function(name,details) {
28                 Item.construct.call(this,name);
29                 this.details=details;
30             },
31             inspect:function(){
32                 print("you see",this.name,",".this.details,".");
33             }
34         });
35         var giantSloth = DetailedItem.create("the giant sloth","it is quietly hanging from a tree,muching leaves");
36         giantSloth.inspect();
37        
38         var SmallItem = Item.extend({
39             kick: function () {
40                 print(this.name,"flies across the room.");
41             },
42             take:function(){
43                 print("you take",this.name,".");
44             }
45         });
46         var pencil = SmallItem.create("the red pencil");
47         pencil.take();
48 
49         object.prototype.isA=function(prototype){
50             function DummyConstructor(){}
51             DummyConstructor.prototype = prototype;
52             return this instanceof DummyConstructor;
53 //instanceof操作符可用于确定一个对象是否基于指定的原型。
54         };
55         pencil.isA(Item);
56         pencil.isA(DetailedItem);
57 
58 
59     </script>
60 </head>
61 <body>
62 
63 </body>
64 </html>

 

posted @ 2015-05-10 17:11  如梦令szy  阅读(132)  评论(0)    收藏  举报